Method of making razor blades



Dec. 29, 1931. T. c. SHEEHAN I' 1,838,116

METHODl oF MAKING RAZOR BLADES Filed March 24, 1956 FIGB FIG. 6

fm fw@ 6 6 22 241 23 24 22 L j llatentecdl Dec.- 29', 1931 STATES PATENT oFFlcE THOMAS COMLINS SHEEI-EIAN, OF UPPER MONTCLIR, NEW JERSEY, ASSIGNOR T O DURHAM DUPLEX RAZOR COMPANY, A

CORPORATION F NEW YORK METHOD OF MAKING RAZOR BLDES .Application filed March 24, 1930. Serial No.f'438,572.

This invention relates to razor blades particularly safety razor bladesvof the flexible double edged type, and to a method of making the same.

' The main object of the invention is to produce an improved safety razor blade which is free from certain defects or disadvantages inherent in most blades of this type. One of these disadvantages is that due to the thinness of the ordinary blade of this type the `edges are not provided with a backing sulliciently rigid for best results. Accordingly it is a principal object of the invention to providea blade which is transversely fle-xble to fitholders whose holding surfaces are transversely curved and at the same time providing an inflexible relatively thick edge section for properly supporting the blade edge.

Another object is to prevent breakage along the mid section of the blade which is weakened by center holes or a longitudinal slot by providing a relatively thick inflexible mid section.

Another obj ect is to provide such a blade in which ample transverse flexibility is attained despite the inflexible mid sections and edge sections by flexible sections connecting the edge section with mid section.

Another principal object of the invention is to provide a method of making razor blades of the above type which will produce cheaper and better razor blades. To this end it is an object of the invention to provide a method for producing thin flexible sections connecting relatively thick inflexible mid and edge sections by rolling and grinding sections of the blade, and by this procedure to produce animproved internal structure to' the steel forming the blade.

Another` object is to provide flexible portions of the blade of suilicient width and of suliciently uniform thickness to distribute bending stress 'over'aconsiderable area thus eliminating breakage. d i

With these and other objects not specifically mentioned in view the invention consists inl certain constructions and-steps which will be hereinafter fully described and specifically set forth in the claims hereunto ap ended.

In the'accompanying drawings w ich form stance of approximately fifteen thousandths a part of this specification and in which like characters of reference indicate the same or like parts,'l*`ig. 1 is a front elevation of rolling means for producing razor blades in accordance with the method of the invention; Fig. 2 isia sectional side elevation of the rolling means shown in Fig. 1; Figy3 is a front eleva-` tion partly broken away of means for producing the improved razor blades .in accordance with the improved method; Fig. ,4 is a front elevation partly broken away ofA ,rerolling means for carrying the invention irito effect; Fig. 5 is a plan view of a razor blade embodying the invention; F ig` 6 is a sectional view on the line 6 6 of Fig. 5.

A razor blade carrying the invention into effect has inflexible edge sections and an inflexible mid section for properly supporting the edge and preventing breakage atthe slotted or perforated mid section, together with flexible sections connecting said edge sections with said mid sections so as to provide Sullicient flexibility to lit curved holders. Preferably the flexible sections are toughened by rolling and rerolling.

The method employed in executing the invention consists in rolling ridges in the steel from which the blade is made grinding od or otherwise removing the tops of the ridges and rerolling the remainder into a symmetrical position with respect to the opposite surface of the steel.

Referring to the drawings, a strip of steel stock of suitable thickness, in the present inof an inch, is heated to the proper temperature and then rolled between a pair of rollers 11 and 12. One of these rollers has a pair of shallowrgrooves 13 about its periphery and the other has a pair of opposed cooperating shallow ridges' 14 extending toward the bottom of the grooveslS. As will be seen from Figs. 1 and2 grooves 13 and ridges 14 are so related that the material of the strip is offset or struck up from the remainder of the strip along the length thereof to produce shallow ridges 24 in the strip. The height of the ridge 24 is in the present embodiment 'approximately nine thousandths of an inch.

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then subjected to a grinding operation such as that shown in Fig. 3.` "'n this grinding operation the upper side of the ridges is ground of'r` iush or nearly flush with the remaining surface of the strip by means of grinding wheel 15 acting in opposition to roller 16 having guiding and supporting ridges 17, leaving a pair of thin sections of approximately six thousandths of an inch in thickness, approximately that of the usual thin flexible blade. Next these thin sections, after the strip has been properly reheated, are by the means illustrated in Fig. 4 rolled or struck back into a symmetrical position with respect to the opposite surface of the steel strip. These means consist of a pair of cooperating rollers 18 and 19 each having opposed low ridges 20 and 21 which serve to `force the material into the symmetrical position referred to and at the same time insure perfect fiatness thereof. after is cut into blades of the shape shown in Fig. 5 and the opposite edges thereof are sharpened to form a blade of the cross section shown, somewhat exaggerated for clearer illustration in Fig. 6, provided with thick inflexible edge sections 22 and a thick inflexible mid section 23 connected by thin flexible sections 24. n

It will be noted that the method described is considerably simpler and cheaper than obtaining the same shape by the relatively diliticult and intricate process of machining or grinding out two grooves on either side of the material. The blade may also be provided with center holes or an axially extending central slot. Since the thin connecting section is of uniform thickness across its considerable width there is no one point at which the greater part of the bending occurs and the bending effect is accordingly distributed over a considerable area thus reducing the chance of breakage. For this reason and because the thickened edge portions are less subjected to burning, the present blade may be given a higher-temper than the usual blade of this type.

\ One advantage of the rolling and rerolling process above stated is that the grain or fiber of the steel, in the strip, is toughened instead of being weakened as would be the case if the material removed were ground or machined away from both sides of the blade. This produces a better blade less liable to breakage and requiring less finishing to attain a smooth polished appearance.

The strip there- Y from steel strip which consists in rolling longitudinal ridges in the strip, grinding of the tops of the ridges, rerolling the remainder into a symmetrical osition with respect to opposite surfaces of) the steel severing the strip into blade lengths, opposite edges thereof.

3. The method of making razor` blades from steel strip which consists in heating the strip, rolling flat longitudinal ridges in the strip, cooling the strip, grinding oif the upper sides of the ridges, reheating the strip andrerolling the remainder of the ridges into symmetrical position with respect to the opposite surfaces of the strip.

In testimony whereof, I have signed my name to this specification.

THOMAS COMLINS SHEEHAN.

and sharpening the 1. The sequence of steps 1n a method of making razor blades which consists in rolling ridges 1n the steel of which the blade is made,

grinding oif the tops of the ridges, and rerolling the remainder into a symmetrlcal po sition with respect to opposite surfaces of the steel.

2. The.meth`od of making razolr blades 

